Ball valves are well known to those skilled in the art and are commonly used in a variety of applications and industries. Typically, in applications that concern controlling the flow of a fluid, an apertured ball valve is selected. In an apertured ball valve, a generally spherical valve member that has a flow aperture or passage formed therethrough is positioned for rotational movement within a valve housing. The valve operation or function is broken down into two separate stages. First, the ball moves between an open and a closed position by rotating through 90 degrees, such that the aperture or flow passage moves from an orientation coaxial with the flow direction, i.e. when the valve is open, to a position whereby the ball aperture is normal or perpendicular to the flow direction. Second, the valve seals in the closed position to prevent flow through the aperture across the ball valve. Therefore, the on-off control of flow through the valve is achieved by rotating the ball through 90 degrees within the valve housing.
In prior art ball valves; the rotation of the ball (i.e., valve member) is typically effectuated by an actuator mechanism that protrudes from the valve housing and is configured to rotate about an axis perpendicular to that of the valve flow. Such a valve is disclosed in U.S. Pat. No. 6,695,285 to Hotton et al.
Several disadvantages are associated with this type of ball valve. For example, the extension of an actuator from the sidewall of the valve is cumbersome and not desirable for applications where space limitations and physical access to the actuator are a concern. Still further, the actuator in these valves must be rotated or turned through at least 90 degrees in order for the valve to move between the fully open and fully closed positions.
Therefore, it would be beneficial therefore, to provide a valve/seal mechanism that is compact, reliable and readily actuated between the open and closed position and actuated with a minimal amount of rotational movement.